Projection device and head-up display

ABSTRACT

A projection device includes: a plurality of light sources arranged in a first direction; a spatial modulation element that modulates incident light into image information and emits the image information; a lens that changes an optical path of light emitted from each of the plurality of light sources such that the light emitted from each light source reaches substantially the same region of an incident surface of the spatial modulation element; and a first reflective optical member that deflects the light emitted from the lens toward the spatial modulation element, the first reflective optical member having a shape that reflects light emitted from the lens so as to be incident on an arbitrary point on the incident surface of the spatial modulation element at a predetermined reference incident angle.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation of U.S. patent application Ser. No. 17/613,261,filed Nov. 22, 2021, which is a National Phase application ofInternational Pat. Appl. No. PCT/JP2020/018764, filed May 11, 2020,which claims the benefit of priority of Japanese Pat. Appl. No.2019-101313, filed May 30, 2019. The entire disclosure of each of theabove-identified documents, including the specification, drawings, andclaims, is incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present disclosure relates to a projection device mounted on avehicle and a head-up display including the projection device.

BACKGROUND ART

In recent years, a head-up display has been developed that displays, fora passenger of a vehicle, an image including information about thevehicle by, for example, a virtual image. Such a head-up display has aproblem of reducing luminance unevenness of a virtual image to bedisplayed.

Under these circumstances, Patent Literature 1 discloses a head-updisplay in which a plurality of light source elements, a first lens, asecond lens, a diffusion member, and a spatial modulation element arearranged in this order, and the first lens changes an optical path oflight emitted from each light source element such that the light emittedfrom each light source element reaches the same region on an incidentsurface of the spatial modulation element.

In addition, a head-up display mounted on a vehicle is required to bemade compact in order to avoid interference with other in-vehiclecomponents. Under these circumstances, Patent Literature 2 discloses avehicle display device in which a reflector having a predeterminedopening angle with a liquid crystal display element is arranged on aback surface side of the liquid crystal display element so as to facethe liquid crystal display element, and a light source is arranged in anopening portion having an opening angle with the reflector and theliquid crystal display element.

Meanwhile, in a head-up display mounted on a vehicle, there is anincreasing need to increase a size of a virtual image. For this purpose,it is necessary to increase a size of a spatial modulation element.Consequently, it is also necessary to increase a thickness of a lensprovided between the spatial modulation element and a light source whileensuring an optical path length between the spatial modulation elementand the light source. As a result, in a backlight unit from a backsurface of the spatial modulation element to the light source, an amountof protrusion in a normal direction of the spatial modulation elementincreases, and mountability of the head-up display on a vehicledeteriorates.

In Patent Literature 1, since the plurality of light sources, the firstlens, the second lens, the diffusion member, and the spatial modulationelement are arranged in series in this order, when the size of thespatial modulation element is increased, the amount of the backlightunit protruding in the normal direction of the spatial modulationelement is increased. Therefore, mountability of the head-up display ofPatent Literature 1 on a vehicle deteriorates.

In Patent Literature 2, since the reflector is merely arranged to facethe liquid crystal display at a predetermined angle, luminanceunevenness cannot be suppressed.

CITATION LIST Patent Literatures

Patent Literature 1: Japanese Patent Application Laid-Open No. 2016-126314 Patent Literature 2: Japanese Patent No. 6078798

SUMMARY OF INVENTION

The present disclosure has been made to solve the above problems, and anobject of the present disclosure is to improve mountability on a vehiclewhile suppressing luminance unevenness of an image emitted by a spatialmodulation element.

A projection device according to one aspect of the present disclosure isa projection device mounted on a vehicle, the projection deviceincluding: a plurality of light sources arranged in a first direction; aspatial modulation element that modulates incident light into imageinformation and emits the image information; a lens that changes anoptical path of light emitted from each of the plurality of lightsources such that the light emitted from each light source reachessubstantially the same region of an incident surface of the spatialmodulation element; and a first reflective optical member that deflectsthe light emitted from the lens toward the spatial modulation element,the first reflective optical member having a shape that deflects lightemitted from the lens so as to be incident on an arbitrary point on theincident surface of the spatial modulation element at a predeterminedreference incident angle.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram illustrating an example of a configuration of ahead-up display according to an embodiment.

FIG. 2 is a diagram illustrating an example of a configuration of aprojection device.

FIG. 3 is a perspective view of the projection device illustrated inFIG. 2 .

FIG. 4 is a diagram illustrating an example of a casing of a head-updisplay according to a modification of the present disclosure.

FIG. 5 is a diagram illustrating an example of arrangement of aplurality of light sources according to the modification of the presentdisclosure.

DESCRIPTION OF EMBODIMENTS

Hereinafter, embodiments of the present invention will be described withreference to the accompanying drawings. Note that the followingembodiments are examples embodying the present invention and do notlimit the technical scope of the present invention.

Hereinafter, the embodiments will be described with reference to theaccompanying drawings. FIG. 1 is a diagram illustrating an example of aconfiguration of a head-up display 10 according to the embodiment. Thehead-up display 10 is mounted on a vehicle 100. The vehicle 100 is, forexample, a moving body such as a four-wheeled automobile. However, thisis an example, and the vehicle 100 may be a railway vehicle, amotorcycle, an aircraft, a helicopter, a ship, and various devices thatcarry persons.

The vehicle 100 includes a windshield 14. The windshield 14 is, forexample, a windshield provided in front of a cockpit of the vehicle 100.The head-up display 10 includes a projection device 11, a reflectiveoptical member 12 (an example of a second reflective optical member),and a casing 13.

The head-up display 10 is a device that projects, onto the windshield14, an image for allowing an observer 101 to visually recognize avirtual image 15.

The projection device 11 includes a backlight unit 20 and a spatialmodulation element 24. The backlight unit 20 illuminates the spatialmodulation element 24. The spatial modulation element 24 is, forexample, a liquid crystal panel. The spatial modulation element 24modulates light emitted from the backlight unit 20 according to a videosignal input from a display control circuit (not illustrated). Themodulated light is emitted from the spatial modulation element 24 astransmitted light.

The spatial modulation element 24 displays an image indicating a stateof the vehicle 100, for example, an image indicating a speed meter or animage indicating a speed of the vehicle 100. The transmitted light whichhas been emitted from the spatial modulation element 24 is guided intoan eye box 102 of the observer 101 via the reflective optical member 12and the windshield 14. Consequently, the observer 101 visuallyrecognizes the virtual image 15. The virtual image 15 displays the stateof the vehicle 100 such as speed. Therefore, the observer 101 can checkthe state of the vehicle 100 through the virtual image 15. The eye box102 is a region where the observer 101 can visually recognize thevirtual image 15 without omission.

The reflective optical member 12 includes a first mirror 121 and asecond mirror 122. The first mirror 121 reflects light emitted from thespatial modulation element 24 toward the second mirror 122. The secondmirror 122 reflects the light from the first mirror 121 toward thewindshield 14. A reflective surface of the second mirror 122 has aconcave shape. Although the reflective optical member 12 includes twomirrors of the first mirror 121 and the second mirror 122, this is anexample, and the reflective optical member may include one mirror orthree or more mirrors. In addition, a refractive optical system such asa lens may be further arranged on an optical path of the reflectiveoptical member 12.

The casing 13 houses the projection device 11 and the reflective opticalmember 12. The casing 13 is, for example, a substantially rectangularparallelepiped. The casing 13 has, on an upper surface thereof, anopening portion 13 a through which light from the reflective opticalmember 12 is emitted. The opening portion 13 a may be provided with atransparent cover.

FIG. 2 is a diagram illustrating an example of a configuration of theprojection device 11. The projection device 11 includes a plurality oflight sources 21 (see FIG. 3 ), a lens 22, a reflective optical member23 (an example of a first reflective optical member), and the spatialmodulation element 24. A diffusion member may be further arranged on anincident surface 22 a side of the spatial modulation element 24, so thatlight distribution characteristics of lights from the plurality of lightsources 21 can be smoothed. The plurality of light sources 21, the lens22, and the reflective optical member 23 constitute the backlight unit20. The spatial modulation element 24 includes an incident surface 24 awhich light enters and an emission surface 24 b from which light isemitted. The incident surface 24 a and the emission surface 24 b havethe same shape. As illustrated in FIG. 3 , the incident surface 24 a andthe emission surface 24 b have, for example, a rectangular shapeincluding a short side 241 and a long side 242.

Note that in the following description, a three-dimensional orthogonalcoordinate system including three axes of an X axis, a Y axis, and a Zaxis orthogonal to each other is set in the drawings. The X axis isparallel to the short side 241 of the spatial modulation element 24. TheY axis is parallel to the long side 242 of the spatial modulationelement 24. The Z axis is parallel to a normal line of the spatialmodulation element 24. Note that a Y axis direction (a longitudinaldirection) is an example of a first direction. A Z axis direction is anexample of a second direction orthogonal to the first direction.

FIG. 3 is a perspective view of the projection device 11 illustrated inFIG. 2 . As illustrated in FIG. 3 , the plurality of light sources 21are arranged in a line in the Y axis direction, for example, at fixedintervals. However, this is an example, and the light sources may bearranged at unequal intervals. Thus, luminance unevenness can besuppressed. Each of the plurality of light sources 21 includes a lightemission surface 21 a. The plurality of light sources 21 are arrangedsuch that a normal line of the emission surface 21 a is parallel to theX axis. The plurality of light sources 21 are, for example, lightemitting diodes (LED). However, this is an example, and the plurality oflight sources 21 may be, for example, laser diodes or organic lightemitting diodes. Note that although in FIG. 3 , four light sources 21are illustrated as the plurality of light sources 21, this is merely anexample, and the number of the plurality of light sources 21 can takeany value of two or more.

Furthermore, the plurality of light sources 21 are arranged such thatthe normal line of the emission surface 21 a intersects the normal lineof the spatial modulation element 24. In FIG. 2 , the normal line of theemission surface 21 a faces an X axis direction, and the normal line ofthe spatial modulation element 24 faces the Z axis direction. Therefore,the normal line of the spatial modulation element 24 and the normal lineof the emission surface 21 a are orthogonal to each other, this is anexample. For example, angles of both the normal lines can be any angleas long as it is an angle other than 180 degrees, and can be, forexample, an angle of 10 degrees or more and 90 degrees or less, an angleof 20 degrees or more and 80 degrees or less, and an angle of 30 degreesor more and 70 degrees or less.

The lens 22 changes an optical path of light emitted from each of theplurality of light sources 21 such that the light emitted from eachlight source 21 reaches substantially the same region of the incidentsurface 24 a of the spatial modulation element 24. Substantially thesame region is intended to allow a slight deviation for a region reachedby light emitted from each of the plurality of light sources 21.Specifically, the lens 22 is arranged close to the plurality of lightsources 21. The lens 22 has a longitudinal direction parallel to the Yaxis direction. The lens 22 includes the incident surface 22 a whichlights emitted from the plurality of light sources 21 enter. The lens 22includes an emission surface 22 b that deflects diverging lights of theplurality of light sources 21 in the Z axis direction into substantiallyparallel lights and emits the substantially parallel lights. Theincident surface 22 a faces the emission surfaces 21 a of the pluralityof light sources 21. One lens 22 is arranged for the plurality of lightsources 21. However, this is an example, and two, or three or morelenses may be arranged for the plurality of light sources 21.

At least one of the incident surface 22 a and the emission surface 22 bof the lens 22 has a convex shape in order to give the lens 22 positiverefractive power. The convex shape of at least one of the incidentsurface 22 a and the emission surface 22 b of the lens 22 isrotationally symmetric with respect to an optical axis. However, this isan example, and at least one of the incident surface 22 a and theemission surface 22 b of the lens 22 may have a toroidal shape havingdifferent curvatures in the Y axis direction and the Z axis direction ora free-form surface shape. A total internal reflection (TIR) lens can bealso used as the incident surface 22 a of the lens 22. This enables thelight from the light source 21 to be efficiently emitted to thereflective optical member 23, resulting in improving light useefficiency. In the present embodiment, the lens 22 is a plano-convexlens in which only the emission surface 22 b has a convex shape.

The emission surface 22 b of the lens 22 has a convex shape with anaspherical form in which curvatures in the Y axis direction and the Zaxis direction are different from each other. Specifically, the emissionsurface 22 b has a curvature in the Z axis direction larger than acurvature in the Y axis direction. The reason why the curvature in the Zaxis direction is made larger than the curvature in the Y axis directionis to narrow down a light beam and guide a parallel light toward theshort side 241 of the spatial modulation element 24. On the other hand,the reason why the curvature in the Y axis direction is made smallerthan the curvature in the Z axis direction is that the light from eachlight source 21 is guided over the entire long side 242. Therefore, inthe spatial modulation element 24 having the Y axis direction as alongitudinal direction and the X axis direction as a lateral direction,the lens 22 is allowed to constitute a lens suitable for light emittedfrom each of the plurality of light sources 21 to reach the same regionof the incident surface 24 a of the spatial modulation element 24.

Furthermore, the emission surface 22 b has a shape in the Y axisdirection, for example, in which the curvature decreases from the centerto the edge so that an illuminance distribution, of the light emittedfrom the plurality of light sources 21, on the incident surface 24 a ofthe spatial modulation element 24 becomes uniform. However, a free-formsurface shape may be provided in order to reduce the luminanceunevenness, and the shape is not limited thereto. In addition, theemission surface 22 b has a shape in the Z axis direction, for example,in which the curvature decreases from the center to the edge so that theilluminance distribution on the incident surface 24 a becomes uniform.However, a free-form surface shape may be provided in order to reducethe luminance unevenness, and the shape is not limited thereto.

The lens 22 is made of a transparent material having a predeterminedrefractive index. The refractive index of the transparent material is,for example, about 1.4 to 1.6. As the transparent material, a resin suchas an epoxy resin, a silicon resin, an acrylic resin, or polycarbonatecan be used. In the present embodiment, the lens 22 is made from, forexample, polycarbonate in consideration of heat resistance.

Reference is made to FIG. 2 . The reflective optical member 23 includesa reflective surface that deflects the light emitted from the lens 22toward the spatial modulation element 24. The reflective optical member23 has a shape that deflects light emitted from the lens 22 so as to beincident on an arbitrary position P on the incident surface 24 a of thespatial modulation element 24 at a predetermined reference incidentangle. Specifically, the reflective optical member 23 has a free-formsurface shape. The arbitrary position P represents a plurality ofpositions on the incident surface 24 a. The reflective optical member 23is, for example, a mirror.

In the head-up display 10, the position, the shape, and the like of thereflective optical member 12 are determined such that the virtual image15 of a target size is displayed at a target display position, and areference incident angle at each of the plurality of positions on theincident surface 24 a of the spatial modulation element 24 is determinedbased on the determined position and shape of the reflective opticalmember 12. Therefore, a shape, of the reflective optical member 23, at aposition P1 as a position where a light beam L1 is deflected toward theposition P, has a shape that causes the light beam L1 to be incident onthe position P at the reference incident angle.

The reference incident angle includes a first component viewed from thelong side 242 of the spatial modulation element 24, i.e., from the Xaxis direction, and a second component viewed from the short side 241,i.e., from the Y axis direction. Therefore, the shape at the position P1is a shape which causes the light beam L1 to enter the position P withthe first component and the second component of the reference incidentangle. Accordingly, the reflective optical member 23 has a free-formsurface shape in which each position P1 causes the light beam L1 to beincident on the corresponding position P on the incident surface 24 awith the first component and the second component of the referenceincident angle. As illustrated in FIG. 3 , at the position P1, acurvature C1 obtained when the reflective optical member 23 is cut alongan X-Y plane is, for example, larger than a curvature C2 obtained whenthe reflective optical member 23 is cut along a Z-X plane. Accordingly,as a whole, a degree of inclination of the reflective optical member 23when viewed from the Z axis direction is larger than a degree ofinclination when viewed from the Y axis direction.

Although the reflective optical member 12 has been here described ashaving a free-form surface shape, the present disclosure is not limitedthereto. As a result of determining the shape at each position P1 of thereflective optical member 23 such that light enters the position P atthe reference incident angle, the reflective optical member 12 may havea flat plate shape or a spherical shape. In this case, the reflectiveoptical member 23 can have a planar shape or a spherical shape.

As described above, according to the present embodiment, the reflectiveoptical member 23 deflects the light beam emitted from the lens 22 andguides the light beam to the spatial modulation element 24. This bringsthe plurality of light sources 21 to be arranged such that the normalline of the emission surface 21 a intersects the normal line of thespatial modulation element 24. As a result, when the size of the spatialmodulation element 24 is increased, an amount by which the backlightunit 20 protrudes in the normal direction of the spatial modulationelement 24 can be suppressed. As a result, the present embodimentenables improvement of mountability of the head-up display 10 on thevehicle 100.

In addition, the lens 22 changes an optical path of light emitted fromeach of the plurality of light sources 21 such that the light emittedfrom each light source reaches the same region of the incident surface24 a of the spatial modulation element 24. Furthermore, the reflectiveoptical member 23 has a shape that deflects light emitted from the lens22 so as to be incident on an arbitrary point P on the incident surfaceof the spatial modulation element 24 at a reference incident angle.Therefore, the present embodiment enables luminance unevenness of animage emitted by the spatial modulation element 24 to be suppressed.

Further, as illustrated in FIG. 3 , the plurality of light sources 21are arranged in parallel with the long side 242 of the spatialmodulation element 24. Therefore, the size of the projection device 11can be reduced as a whole as compared with a case where the plurality oflight sources 21 are arranged in parallel with the short side 241 of thespatial modulation element 24. This enables further improvement ofmountability of the head-up display 10 on the vehicle 100.

Note that the present disclosure is allowed to adopt the followingmodification.

-   -   (1) FIG. 4 is a diagram illustrating an example of the casing 13        of the head-up display 10 according to the modification of the        present disclosure. In FIG. 4 , the casing 13 includes an        attachment portion 131 to which the projection device 11 is        attached. The attachment portion 131 is a bottomed hole        extending obliquely from an opening portion 133 in a bottom        surface 132 of the casing 13. A cross section of the attachment        portion 131 has the same shape as a cross section of the        projection device. Therefore, the projection device 11 is fitted        into the attachment portion 131 by insertion into the casing 13        in an arrow direction. A bottom surface 134 of the attachment        portion 131 is open. Accordingly, the light emitted from the        spatial modulation element 24 is taken into the casing 13 and        guided to the windshield 14 via the reflective optical member 12        and an opening portion 13 a illustrated in FIG. 1 .    -   (2) Although in the modification (1), the spatial modulation        element 24 is provided inside a casing 11 a of the projection        device 11, this is an example. The spatial modulation element 24        may be provided on the bottom surface 134 of the attachment        portion 131.    -   (3) Although in the example of FIG. 3 , the plurality of light        sources 21 are arranged in a line in the Y axis direction, this        is an example. FIG. 5 is a diagram illustrating an example of        arrangement of the plurality of light sources 21 according to        the modification of the present disclosure. As illustrated in        FIG. 5 , the plurality of light sources 21 may be arranged in a        matrix of predetermined rows x predetermined columns in the Y        axis direction and the Z axis direction. As a result, an image        having sufficient luminance can be obtained in a case where the        spatial modulation element 24 is enlarged.    -   (4) Although in the example of FIG. 1 , the head-up display 10        displays the virtual image 15, the present disclosure is not        limited thereto, and an image may be displayed on a part (for        example, a console box or the like) of the vehicle 100.

A projection device according to one aspect of the present disclosure isa projection device mounted on a vehicle, the projection deviceincluding: a plurality of light sources arranged in a first direction; aspatial modulation element that modulates incident light into imageinformation and emits the image information; a lens that changes anoptical path of light emitted from each of the plurality of lightsources such that the light emitted from each light source reachessubstantially the same region of an incident surface of the spatialmodulation element; and a first reflective optical member that deflectsthe light emitted from the lens toward the spatial modulation element,the first reflective optical member having a shape that deflects lightemitted from the lens so as to be incident on an arbitrary point on theincident surface of the spatial modulation element at a predeterminedreference incident angle.

According to this configuration, the first reflective optical memberdeflects light emitted from the lens and guides the light to the spatialmodulation element. Accordingly, this configuration allows the pluralityof light sources to be arranged such that a normal line of an emissionsurface intersects a normal line of the spatial modulation element. As aresult, when the size of the spatial modulation element is increased,this configuration enables suppression of an amount by which a backlightunit from the light source to the spatial modulation element protrudesin the normal direction of the spatial modulation element. As a result,this configuration enables improvement of mountability of the head-updisplay on a vehicle.

In addition, the lens changes the optical path of the light emitted fromeach of the plurality of light sources such that the light emitted fromeach light source reaches the same region of the incident surface of thespatial modulation element. Furthermore, the first reflective opticalmember has a shape that deflects light emitted from the lens so as to beincident on an arbitrary point on the incident surface of the spatialmodulation element at the reference incident angle. Therefore, thisconfiguration enables luminance unevenness of an image emitted by thespatial modulation element to be suppressed.

In the above aspect, the first reflective optical member may have afree-form surface shape.

According to this configuration, since the first reflective opticalmember has the free-form surface shape, it is possible to easily makelight emitted from the lens be incident on an arbitrary point on theincident surface of the spatial modulation element at the referenceincident angle.

In the above aspect, the plurality of light sources may be arranged suchthat a normal line of an emission surface intersects a normal line ofthe spatial modulation element.

According to this configuration, since the plurality of light sourcesare arranged such that the normal line of the emission surfaceintersects the normal line of the spatial modulation element, an amountby which a backlight unit from the light source to the spatialmodulation element protrudes in the normal direction of the spatialmodulation element can be more reliably suppressed. As a result, thisconfiguration enables further improvement of mountability of the head-updisplay on a vehicle.

In the above aspect, the first direction may be parallel to alongitudinal direction of the spatial modulation element.

According to this configuration, since the plurality of light sourcesare arranged in parallel to the longitudinal direction of the spatialmodulation element, the projection device can be downsized as comparedwith a case where the plurality of light sources are arranged inparallel to a lateral direction of the spatial modulation element.

In the above aspect, the lens may have a convex surface at least as theemission surface.

According to this configuration, it is possible to easily realize a lensthat changes an optical path of light emitted from each of the pluralityof light sources such that the light emitted from each light sourcereaches the same region of the incident surface of the spatialmodulation element.

In the above aspect, the emission surface of the lens may have a largercurvature in a second direction than a curvature in the first direction,the second direction being orthogonal to the first direction.

According to this configuration, since in the spatial modulation elementhaving the first direction as a longitudinal direction and the seconddirection as a lateral direction, a lens can be configured which issuitable for light emitted from each of the plurality of light sourcesto reach the same region of the incident surface of the spatialmodulation element.

In the above aspect, the plurality of light sources may be arranged in amatrix in the first direction and the second direction orthogonal to thefirst direction.

According to this configuration, an image having sufficient luminancecan be obtained in a case where the spatial modulation element isenlarged.

A head-up display according to another aspect of the present disclosureincludes the above-described projection device; and a second reflectiveoptical member for projecting light emitted from the spatial modulationelement onto a reflective member provided on the vehicle.

According to the present configuration, it is possible to provide ahead-up display having improved mountability on a vehicle whilesuppressing luminance unevenness of an image emitted from the spatialmodulation element.

INDUSTRIAL APPLICABILITY

The present disclosure is applicable to a device that is mounted on avehicle and displays video such as a virtual image.

What is claimed is:
 1. A projection device mounted on a vehicle,comprising: a plurality of light sources arranged in a first direction;a display element in which light from the light source incident andemits image information; a lens that guides the optical path of lightemitted from each of a plurality of light sources in the direction ofthe incident plane of the display element; and a first reflectiveoptical member that deflects the light emitted from the lens toward thedisplay element, wherein the first reflective optical member has a shapethat deflects light emitted from the lens so as to be incident on anarbitrary point on the incident surface of the display element at apredetermined reference incident angle.
 2. The projection deviceaccording to claim 1, wherein the first reflective optical member has afree-form surface shape.
 3. The projection device according to claim 2,wherein a first curvature in a first direction at a first point of thefirst reflective optical member is different than a second curvature ina second direction different from the first direction at the first pointof the first reflective optical member.
 4. The projection deviceaccording to claim 1, wherein the first reflective optical memberreflects the light emitted from a plurality of light sources.
 5. Theprojection device according to claim 1, wherein the plurality of lightsources are arranged such that a normal line of an emission surfaceintersects a normal line of the display element.
 6. The projectiondevice according to claim 5, wherein an angle of the normal line of theemission surface and the normal line of the display element is not lessthan 10 degrees nor more than 90 degrees.
 7. The projection deviceaccording to claim 5, wherein the first direction is parallel to alongitudinal direction of the display element.
 8. The projection deviceaccording to claim 1, wherein the lens has a convex surface at least asthe emission surface.
 9. The projection device according to claim 8,wherein the emission surface of the lens has a larger curvature in asecond direction than a curvature in the first direction, the seconddirection being orthogonal to the first direction.
 10. The projectiondevice according to claim 1, wherein the plurality of light sources arearranged in a matrix in the first direction and the second directionorthogonal to the first direction.
 11. The projection device accordingto claim 1, wherein the lens changes the optical path of light emittedfrom each of the plurality of light sources such that the light emittedfrom each light source reaches substantially the same region of anincident surface of the display element.
 12. The projection deviceaccording to claim 1, wherein the lens is composed of a plurality oflenses.
 13. The projection device according to claim 1, wherein the lensis made from resin.
 14. A head-up display comprising: the projectiondevice according to claim 1; and a second reflective optical member forprojecting light emitted from the display element onto a reflectivemember provided on the vehicle.
 15. The head-up display according toclaim 14 further comprising: a casing that accommodates the projectiondevice and the second reflective optical member and has an openingportion for emitting projecting light reflected by the second mirror,wherein a normal line of the opening portion and a third direction inwhich the light source emits light intersect.